1. Field of the Invention
The present invention relates to a manipulation mechanism for selectively locking or unlocking the locking mechanism of a baby carriage, and more particularly relates to a remote manipulation mechanism disposed on the handlebars of a baby carriage.
2. Background
Collapsible baby carriages are known. Also, it is know to design the handlebars so that they can alternatively be positioned so as to extend forwardly or rearwardly of the seat so that the carriage can be pushed in the backward or forward direction, respectively. Each of these carriages includes a locking device for locking the carriage in the upright position and locking the handlebars in the forward or backward position. A locking/unlocking manipulation mechanism is disposed at the upper end of the handle bars so that the locking device can be activated from a remote, more convenient position, as disclosed in Japan Utility Model Applications (OPI) Nos. 48866/86, 139859/86 and 34766/88 (the term "OPI" as used herein means an "unexamined published application").
The manipulation mechanism includes a manipulation lever pivotally supported at the central portion thereof in a housing so as to be rotatable and a remote manipulation wire anchored at one end thereof to an end of the lever and at the opposite end to the locking device. The manipulation portion of the lever, which projects from the housing, is rotated rightward or leftward to operate the wire for the manipulation mechanism.
With such a design, the operating stroke of the remote manipulation wire is a function of the ratio of the distance between the point at which the wire is secured to the lever and the pivot point at the central portion of the manipulation lever to the distance between the pivot point and the butt of the lever where the manipulation force is applied. Therefore, the latter distance needs to be maximized in order to minimize the required manipulation force to actuate the locking mechanism. However, when the distance between the pivot point and the butt of the lever is increased, the size of the locking/unlocking manipulation mechanism becomes correspondingly larger. On the other hand, if the operation stroke of the wire is increased while the distance between the pivot and the butt of the lever is decreased, the required actuation force becomes larger in inverse proportion to the ratio, making it difficult to rotate the lever and actuate the locking mechanism. Further, the locking device can be inadvertently unlocked if the manipulation lever projecting from the housing is accidentally touched during the movement of the baby carriage. To prevent such a problem, the shape of the lever or the construction for engaging the lever with the housing needs to be specially designed. However, such a special design results in a complicated assembly of the baby carriage and increased cost thereof.
The present device was made in order to solve the problems described above. Accordingly, it is an object of the present invention to provide such a locking/unlocking manipulation mechanism on the handlebars of a baby carriage where the operation stroke of a manipulation wire can be made sufficiently long although the manipulation space is small.
It is another object of the invention to provide such a locking/unlocking manipulation mechanism on the handlebars of a baby carriage which includes a sliding prevention stopper for preventing the manipulation lever from being inadvertently moved so that the locking means will remain locked.